Unitary air conditioners, also known as room air conditioners, have all of the components of a central air conditioning system but all of the components are contained within a single housing. This means that the condenser, evaporator, expansion valve, compressor, exterior fan, and interior fan are generally contained within a single housing.
Unitary air conditioners are often used in buildings where there are multiple individual living spaces, such as in apartment buildings and office buildings. Within each living space, an occupant may have individual control over each respective unitary air conditioner that is supplied to cool a particular living space. In warm weather months or in warm weather climates, multiple unitary air conditioners operating at the same time can create tremendous loads on electric power grids.
Conventional approaches have suggested to power “on” unitary air conditioners in a staggered manner by completely eliminating power to a certain number of unitary air conditioners while allowing other unitary air conditioners to “run.” While this approach of completely eliminating power to a select group of air conditioners is effective for reducing energy loads on electric power grids, this approach does create problems for the occupants who have the unitary air conditioners which are shut “off.”
One problem is that when an unitary air conditioner is completely in an “off” state in which all mechanical components are not operational and not receiving any power, then air within the living space cooled by the unitary air conditioner does not circulate. When air does not circulate in a warm living space, an occupant may perceive the air to be stagnant and more hot than can be tolerated. Further, the occupant of the living space may be inclined to try and turn “on” a unitary air conditioner unit which has been placed in the “off” state to conserve power.
Accordingly, there is a need in the art for a method and system for controlling unitary air conditioners in a manner such that air within a living space is not permitted to become stagnant, while at the same time, reducing peak loads in order to prevent overloading of an electric grid.